The EX: Delta Species set is the eleventh third generation set. This set introduced the new feature of Delta Species Pokémon. The Delta Species Pokémon are Pokémon whom are of a different type than normal. These cards also had a different visual style to normal. This set also introduced Holon's Pokémon. These Pokémon are rather unique in that as well as being Pokémon, they can also be used as Energy cards for your Pokémon. It also was the first set to have Ditto take different forms and thus different types.